There are three main strategies to get out of the coronavirus lockdown, but each exposes us to the risk of a second wave of infections and further blocks if things do not go as planned.
Bans, curfews and restrictions on daily life for half of the planet's population have become the new normal. But as we adjust to these coronavirus measures, what prospect is there of returning to the "old normal"? What is the exit strategy from the coronavirus?
If you are hoping for a return to your old life, I have good news and bad news: it will happen, but I don't think soon. "It is absolutely true that government consultants and researchers are considering the issue of a coronavirus exit strategy". To say it is the epidemiologist Mark Woolhouse of the University of Edinburgh, UK. But what will the exit strategies of the different nations be? The lack of coordination at the international level could lead to problems of "patchy" infections.
The lockdowns that many nations are enduring are a short-term strategy to reduce the average number of infections and stop their exponential growth. With a term you've heard for weeks, "flattening of the curve". The approach aims to prevent hospital overload, reduce the number of deaths and buy time to increase beds, understand the virus and find new treatments.
However, blocking is not a long-term strategy.
"We want to get out of the way because of all the damage it is doing, economically and psychologically," he says. Woolhouse. But removing the restrictions can cause the infection rate to grow exponentially again.
Developing an exit strategy, therefore, becomes a question of determining the best time to eliminate the restrictions and the actions to be taken to keep a return of infections under control.
Don't count on the vaccine
One thing is clear: we can't count on a vaccine to get us out of this. It takes many months to develop an effective one, if we can do it. And then waiting for a vaccine is not a strategy: it is more in the field of hope.
So how to get out of the way without unleashing a dangerous second wave of infections among people who weren't exposed to the virus the first time? A second wave like this is "highly likely," he says Susy Hota, Medical Director of the Infection Prevention and Control Program at the University Health Network of Toronto, Canada.
Sure, each second wave is likely to be less severe than the first, Woolhouse says.
"With any new virus emerging, the first wave is always the worst. Then it becomes much more manageable." For example, from the Zika outbreak from 2015 to 2016, subsequent outbreaks tend to fade due to the detection and control measures currently in place, as well as a greater degree of immunization in the population.
The exit strategy must therefore include a plan to manage a second wave. There are three ways to do this: we can call them upkeep, build, and shield.
Retention
The maintenance strategy is long-term: blocking until the rate of new infections approaches zero. Even if waiting for an infection rate close to zero risks imposing a block for a long time.
In phase two, when the rate falls, off the block and aggressive containment strategy. This means diagnosing second wave cases as quickly as possible, isolating them, tracing their contacts, and isolating them too to cut off all new transmission lines.
This requires developing a far better ability to trace contacts than we do today.
Construction
The second strategy, building, buys health services time to recover from the first wave and have the ability to deal with the second. In wealthier nations, the limiting factors of health services are beds, equipment, and intensive care personnel. So this strategy involves a block long enough to allow for these 3 factors. In phase two, gradually release the restrictions and deal with the second wave, hopefully with a much lower death rate. But how much ICU capacity does it take to achieve this? It's a hard question. And one wrong answer can cost many, too many lives.
Shield
Option three, the shield, is to abruptly end the block, extensively protecting those who are arguably the most vulnerable to the virus. This means finding ways to ensure the safety of the elderly, immunosuppressed and sick with other diseases. Succeeding requires widespread community screening to find out who is contagious (especially asymptomatic ones) and make sure they don't come into contact with vulnerable people.
Another element of this exit strategy from the coronavirus is the development of antibody tests to identify medical personnel and health workers who have already recovered and therefore with less risk of infecting others.
The effect would be to reduce critical cases and deaths. Reduce the pressure on hospitals while allowing for the famous "herd immunity". Covid-19 could continue to affect (and rarely kill) young people with no other health conditions. However, protection would reduce the number of cases among the most vulnerable people, allowing health services to better treat them.
Which exit strategy is more valid?
The choice between these three strategies largely depends on some unknowns. In particular, the speed with which a population exceeds the threshold of healed necessary for herd immunity. It is the time when enough people have acquired antibodies to the virus and prevent it from rapidly circulating in the population.
We still don't know if recovery from covid-19 make you immune to the virus in the long term. But even if immunity were only temporary, when enough people recover, herd immunity will slow or stop its spread for a while.
If none are valid?
Each coronavirus exit strategy among these three may also have to be abandoned or suspended if the second wave gets out of hand, which could mean a repeated cycle of lockdowns, openings, new lockdowns. It is certainly possible that once the lock is released it may need to be reintroduced.
If we are successful, we will have crushed the contagion curve but then we must not suddenly return to our normal way of life. It would be quite dangerous.
If we stop, all our efforts will be wasted and we could potentially see a second peak.
We need to maintain the measures and then gradually adjust some of them, to cautiously lead us towards a new normal.
Chance of success for any coronavirus exit strategy? Unknown.
Un recent study on how the outbreak in the UK could unleash in the next 18 months he concluded that "the inherent randomness of social processes can lead to a wide range of possible outcomes". A very elegant formula to say that not enough is yet known.
"Models are based on important assumptions and often these assumptions are wrong", says the virologist Jonathan Ball of the University of Nottingham, UK. "Although such models can give an idea of what might happen, they cannot tell us what will happen and the sooner we understand it, the better.". There is no substitute for field research, she says.
Learn from China
For this, many are looking to China, the initial center of the pandemic. "China was the first nation to enforce the blockade", says the epidemiologist Caroline Walters at Imperial College London. "So, since I'm a bit ahead, I think everyone is considering how they are handling the situation."
China has basically followed the tightening strategy, imposing strict social distancing on Wuhan in Hubei Province from 23st January, the (official) start of the epidemic. The 23 March, for the first time since the outbreak began, five consecutive days had gone by with no new cases in the country. The restrictions have now been relaxed, including in much of Hubei, and will also be lifted in Wuhan tomorrow April 8.
"Life did not return to normal, but they slowly started letting people move a little more"Walters says. "They are no longer stuck as they were before."
Early signs suggest that China has somehow successfully emerged from the strict social distancing.
Consequently, economic activity seems to restart, second a recent study of Imperial College London's COVID-19 response team, of which Walters is a member.
The team obtained a set of motion level data in major cities in each mainland China province between January 1 and March 17, acquired by Chinese search engine Baidu's phone location-based services.
The researchers found that levels of movement closely correlated with the number of new cases in the first analysis period. People were spreading the virus in their daily lives. But once containment measures were enforced and then loosened, that correlation disappeared.
"Transmission remained low, despite people being able to move," Walters says. "We are seeing some people able to return to normal economic activity without the virus returning to the same level of transmission."
All we are looking at is correlation, not causation.
We cannot say directly "this caused this other". The results cannot rule out further outbreaks. Last month, China's service and manufacturing sectors reported a return to growth after a severe slump in February. China's National Bureau of Statistics says more than half of businesses have returned to work, although it warns that the Chinese economy has not yet returned to normal.
Reports are also emerging that some recently reopened businesses, such as cinemas and bars, are suddenly shut down again. Authorities don't explain these closures, second a Washington Post report . The possibility of a new round of infections remains relatively high. Epidemiologists claim that if a second wave hits China, it will be evident by the end of this month.
So can China serve as a model for the rest of the world?
To some extent, yes, but the coronavirus exit strategy will have to be adapted to local conditions. Not all countries will have the ability to perform testing or contact tracing, for example.
The European Union has stated that it is working on a coordinated exit strategy , but there are still no details and today's meeting between the ministers of the various European states does not bode well.
Until now, exit strategies have been managed nationally or transnationally rather than internationally, despite the outbreak being a pandemic.
WHO said there is no global exit strategy yet, saying the organization is currently focusing on responding to the virus.
Whatever coronavirus exit strategy is put in place, it is likely that we will eventually return to something that resembles our old lives.
"We have to find a way to live with this virus and still work more or less as usual", he claims Woolhouse. Maybe we will live with this virus forever, but certainly for the foreseeable future.
So the long-term strategy is "how do we live with covid-19?
Within a year or so, vaccines could become part of the answer and even improved treatments and some level of herd immunity will play a role in the global exit strategy from the coronavirus.
"I think we'll go back to our old lives," Walters says. “Pandemics have already happened. These measures are not eternal. They were introduced to achieve a certain goal, which is the flattening of the curve to protect our healthcare system. We don't know exactly when it will end. But it will end. "
